[Mk2] [Turbo] Rad Fans coming on when car starts up, how to stop this?

[gline]

The previous owner of my tubby has the radiator fans coming on immidiatly when you turn the key over, they only turn off when you turn the engine off.

How do I put it back to standard so that they come on only whne it reaches a certain temp ?

Reason I ask is because I eventually want to hook my chargecooler unit up and I want the chargecooler pump to come on at a certain temp.

Also is there any benifit to adding a SPAL fan to the cinquecento rad I have for the chargecooler? i will be mounting it in front of the engine rad

[Razor04]

Are you sure its the rad fans? & not the intercooler fan? a common mod is to disconnect the engine bay temp sensor (attatched to underside of engine lid) this will put the intercooler fan into failsafe mode so it runs all the time. From ignition to switch off. The mod is to reduce heatsoak from the engine on the intercooler.

[gline]

Are you sure its the rad fans? & not the intercooler fan? a common mod is to disconnect the engine bay temp sensor (attatched to underside of engine lid) this will put the intercooler fan into failsafe mode so it runs all the time. From ignition to switch off. The mod is to reduce heatsoak from the engine on the intercooler.

yeh its definitly the front rad fans that come on as you can hear and see them when you lift the frunk bonnet.

[paul port]

He has most likely disconnected the temperature sensor from the front radiator... That would be the quickest way to do it... forces the Aircon/Heater ECU into a safe mode of operation

paul

[gline]

Where exactly is it located? any pics at all?

[paul port]

On the Radiator
Seriously... Just lay on your back and look up, it's on the RHS if I recall

[Pbgts]

Hi mate i dont think the old owner has switched the fans to run this way, ive got the same problem as you and its done my head in for over 3 months now. Ive checked everything ,relays,switches,air con ,sencors,e.t.c has your air con stopped working ??

[gline]

Hi mate i dont think the old owner has switched the fans to run this way, ive got the same problem as you and its done my head in for over 3 months now. Ive checked everything ,relays,switches,air con ,sencors,e.t.c has your air con stopped working ??

well the air coming out is warm so im assuming yes.
However I think i see the temp sensor unplugged near the fan, but i cant see where it plugs into.

[Pbgts]

The fan temp sencor is on the drivers side bottom of the rad its got 2 wires that fit into the connector ,ive tried two new temp sencors in the rad but still nothing so dont waste ya money on them

[gline]

The fan temp sencor is on the drivers side bottom of the rad its got 2 wires that fit into the connector ,ive tried two new temp sencors in the rad but still nothing so dont waste ya money on them

I can see the 2 pin connector , but i cant see where this goes into, il have to jack up the car and get under there. Wasnt gonna buy a new sensor, just plug the old one in, if it doesnt work i'll just have to live with thee fans on all the time

Also the IC fan is on all the time, so il have to check the engine bay sensor too. Man i must be eating a fair bit more petrol with all those fans on all the time

[paul port]

The fan temp sencor is on the drivers side bottom of the rad its got 2 wires that fit into the connector ,ive tried two new temp sencors in the rad but still nothing so dont waste ya money on them

I should point out...
If the car has Aircon (EG an Import) then the sensor mounted in that hole is DIFFERENT to say a UK car Without Aircon - despite the connector being the same (If memory serves)

With Aircon: Sensor is a Thermistor 'Temperature Sender' - tells the Aircon ECU the temperature of the water

No Aircon: Sensor is a Thermostat-Switch - Simply switches on/off at a given temperature

Fit the wrong one in either car, and the fans will run continuously

[Pbgts]

Looking at the wiring diagrams all 3 fans are linked ,ive checked the votage and the wiring continuity to all sencors and checked the earths , relays My problem started one morning about 3 months ago i started the car and my 2 fans came on and stayed on ,it didnt happen after changing any parts or anything my old switch works fine ive tested it in boiling water and it switches

[Benmoore999]

nothing to do with the aircon pressure sensor being unplugged in the frunk ? If you unplug that the rad fans will stay on all the time.